Over-The-Top Media Service Testing and Qoe Issues Isolation

2. The method as claimed in claim 1, wherein each selected test agent is implemented as a HAS client.

3. The method as claimed in claim 1, wherein the test agents act both as HAS clients and HAS servers.

4. The method as claimed in claim 1, wherein the test agents are simulating HAS media client playback by downloading media segments from the HAS server according to a particular HAS protocol.

5. The method as claimed in claim 1, wherein the configuration parameters of the selected test agents are at least one of a) target Uniform Resource Locator (URL) address, b) content delivery quality parameters, and c) buffering target.

6. The method as claimed in claim 5, wherein said target URL address is a URL parameter which directs to a reference video hosted on a video server.

7. The method as claimed in claim 5, wherein said target URL address is a parameter which directs to a previous test agent acting as the HAS server in the service delivery path.

8. The method as claimed in claim 5, wherein a video delivery quality value represents format, resolution, video encoding, audio encoding and frame rate of the video resource.

9. The method as claimed in claim 5, wherein a buffering target value represents an amount of video content that each test agent attempts to fetch in advance of the current play time during video streaming.

10. The method as claimed in claim 4, wherein roots of the DAG are test agents requesting the OTT media from a streaming service server.

11. The method as claimed in claim 1, wherein the collected metrics are at least one of a) total loss from a root to the client agent (PerfTL), b) the current loss (PerfCL) between each pair of consecutive test agents, and c) the initial loss on a root test agent (PerfIL).

12. The method as claimed in claim 1, wherein the influence factors are at least one of a) number of stalling events, b) total duration of stalling events, c) average interval between stalling events, and d) length of content.

13. The method as claimed in claim 1, wherein said QoE score is a quality estimation score.

14. The method as claimed in claim 13, wherein said quality estimation score is based on the ITU-T P.1203 Parametric bitstream-based quality assessment of progressive download and adaptive audiovisual streaming services over reliable transport.

15. The method as claimed in claim 1, wherein the media service is media streaming service and the media resource is an audio, video, or audio-video resource and the content segments are video segments.

16. The method as claimed in claim 15, wherein said resource includes at least two tracks, where one track is a video track and another track is an audio track.

17. The method as claimed in claim 13, wherein comparing said quality estimation score of said test agents includes evaluating a total loss from a first to a last agent of a chain (PerfTL), a current loss (PerfCL) between each pair of consecutive test agents and an initial loss (PerfIL) on the first test agent.